The present disclosure relates generally to a method and apparatus for additive manufacturing and, more particularly, to a method and apparatus for a current load monitoring algorithm that provides a quantitative evaluation of component distortion due to residual thermal stresses.
Laser Powder Bed Fusion (LPBF) is an additive manufacturing process involving construction of a three-dimensional article by selectively projecting a laser beam having a desired energy onto a layer of particles. When coupled with computer aided design apparatus, LPBF is an effective technique for producing prototype as well as mainstream production articles. Other such additive manufacturing processes utilize an electron beam within a vacuum.
An LPBF system utilizes a rigid recoater blade system for high precision deposition of micron level powder layers that may be adjusted by material and a desired compromise between speed and surface finish. Although effective, the rigid recoater blade system may be subject to thermal stresses that cause distortions especially in relatively thin wall components with high aspect ratios. Oxygen content variation influences the absorption rate of laser radiation, which changes melt pool formation and liquid metal surface tension. These and other factors may negatively impact a fusion process between adjacent scanning paths and deposited layers which may often cause excessive volumetric growth of rapidly solidified material such that the rigid recoater blade may jam on the distorted areas of the fused layer and cause a process interruption.